#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (ll i=a;i<b;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}


void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	cin>>t;
	rep(i,0,t) solve();
}

void solve(){
	ll x,y,a;
	cin>>x>>y>>a;
	ll ans=abs(x-y);
	if(y==0){
		ll b=0;
		do{
			b++;
			x/=a;
			chmin(ans,x+b);
		}while(x);
		cout<<ans<<"\n";
		return;
	}
	
	int M=2;
	vector<ll> dp(M,ILL);
	dp[0]=0;
	vector<ll> val={y,y+1};
	while(true){
		rep(i,0,M) if(val[i]>=0){
			ll b=0,tmp=x;
			while(true){
				chmin(ans,dp[i]+abs(tmp-val[i])+b);
				if(tmp<=val[i]) break;
				tmp/=a;
				b++;
			}
		}
		if(val[0]<=0) break;
		vector<ll> n_val={val[0]/a,val[0]/a+1};
		vector<ll> n_dp(M,ILL);
		rep(i,0,M) rep(j,0,M){
			if(n_val[j]<0) continue;
			ll cost=abs(val[i]-n_val[j]*a)+dp[i]+1;
			chmin(n_dp[j],cost);
		}
		swap(n_val,val);
		swap(n_dp,dp);
	}
	cout<<ans<<"\n";
}